Multiple brush selector with mechanical brush selection



F. MERK Jan. 24, 1933.,

MULITIPLE BRUSH SELECTOR WITH MECHANICAL BRUSH SELECTION 3 Sheets-Sheet1 Filed June 2, 1932 F. MERK 1,895,265

MUhT IPLE BRUSH SELECTOR WITH MECHANICAL BRUSH SELECTION Jan. 24, 1933Filed June 2, 1952 H a w W W 3 w x w/ g w w w d 0 v 12345 7 :1 a 5 L 0 imy Q Q m LOU 234 67890 l 1 I l I t I ll 5 Z 3 MW a a a w M w W w w x a all "HUN/H iw/OU W "N w w M FRIEDRICHMERK Jan. 24, 1933.

F. MERlf Filed June 2, 1932 3 Sheets-Sheet 3 Ill/- Q25: :TB 2 0\lurlllll. 6 v a a M a a w u a Patented Jan. 24, 1933 :PT'E

T OFFICE I FRIEDRICH MERK, OF FRANKFORT-ON-THE-MAIN, GERMANY MULTIPLEBRUSH SELECTOR WITH MECHANICAL BRUSH SELECTION Application filed June 2,1932, Serial No. 615,011, and in Germany June 2, 1931.

This invention relates to selectors for telephone installations, whereina switch member is provided with a'plurality of brush sets mounted on acommon carrying support and adapted to be rendered separately operativemechanically (for example by means of a push rod) for making contactwith'each of a group of line contacts, the rendering operative of theset of brushes coming into question at any time being effected by apreceding corresponding setting'of the switch member. Such a selector isdescribed for'exan plein my prior U. S. Patent No. 1,849,986 dated March15, 1932 for an improved automatic telephone switch. i

The invention has for its object an improvement in such selectors andthis result is obtained by adding a'controllingswitch which in one ofit's positions mechanically'completes or performs the functionofrendering'operative the set of brushes prepared forthe se lection. v

The arrangement accordingto'the invention relates to fundamentally newmethod of use of a control switch, as this in addition to the usualswitch operations (changing over contacts) is also used for mechanicalswitching operations. This enlarge d'method of use of a control switchhas abovelall, in connection with the multiple brush selectors abovereferred to, considerable advantages which are not obtained with'theknown selectors. In multiple brush selectors there are various switchingoperations which when setting the selector switch member are subsidiaryand cannot be carried out by the switch member itself. To thisappertains in any case the completion of the brush selection, for whicha separate electro-magnet was hitherto necessary, which, however, cameinto operation temporarily only once on each use of the selector, andthen could not be further used. This electro-magnet according to theinvention is omitted or rather is replaced by the electro-magnets of avaluable control switch. In addition it is avoided with certainty thatduring a selector setting, the arrangement for the mechanical select-ionof brushesis actuated a number of times and thus various sets of brushesare successively rendered operative. This is prevented by the controlswitch in that it only permits of the completion of the brushselectionin a predetermined switching position.

An example of construction of the invention is illustrated in theaccompanying drawings. In these, a selector is shown as forming thebasis of the example of construction, but the use of the invention isnot limited to this selector type alone, since it extends also to othermultiple brush selectors (rotary selcctors) with mechanical brushselection and preparation thereof by a preceding switch member setting.L

In said drawings: 1

Figures 1 and 2 in front and side elevation'respectively illustrate thecomplete selector constructed according to the invention.

Figures 3 and 4 are enlarged illustrations in front elevation andlongitudinal section respectively of the particularly interestingsetting mechanism with control switch, omitting the parts in frontofthe'switch and control member. v

Figures 3a and 3?) represent an indicating device for the switch member,already illustrated in Figure 3, in difl'erent positions thereof. I A aFigure 5 shows an auxiliary switch memher almost covered in Figure 3.

Figures 6 tot) show'the control member and a push rod serving forinserting the brush sets in different operative positions.

Figure 10 is a'view illustrating the coupling of the control member tothe switch member when returning both.

Figures 11 to 13 are different views of an intermediate member (pushmember) for actuating the push rod. f

In connection with the following description of one practicableconstruction, the separate features of the invention will be'describedwhich reside particularly in the construction of the controlswitch'ma'king it suitable both for effecting the mechanical brushselection as also for other purposes peculiar to multiple brushselectors.

Such a purpose occurs in connection with the regulation of the movementof an auxiliary switch member, associated with 100 the switch member,which is adapted only to partake of the movement of the switch memberafter a certain movement thereof. For the coupling of the auxiliaryswitch member with the switch member for this purpose, there would againbe necessary a separate electro-magnet, which would be insuiiicientlyused, in so far as it'is required that the movement of the auxiliaryswitch member is to begin at a suitable predetermined phase of theswitch member setting.

This requirement is satisfied in the arrangement of a control switchaccording to the invention in that the control switch again causes inone of its positions the movement of the auxiliary switch member by themechanical actuation of a coupling member.

A further problem solved by the control switch and auxiliary switchmember isin connection with rendering the switch setting noticeable byan indicating device in multiple brush selectors with a switch memberwhich is adjustable in the same direction before and after the brushselection. Such an indicating device is entirely novel for this type ofselectors. For operatively carrying out the idea of the invention, thedrive for the selector switch member and for thecontrolmember isregulated, in the present example of. construction, ina unitary manner.so that for the-setting of-both devices (switch member a.nd2.coritrolswitcl1), their ownstored forces (gravityor springs) are used, and the'renewal ofithese' stored forces expended during theadjustment, isproduced, for example,

at the end of each use of the selector by a common driving device fedfrom the outside. The particular advantage of this arrangement residesin a far reaching relieving of the load; ofthe'electro-magnet whichregulates the setting of the switch member and of the control switch, inthat these have onlyto carry out a release operation, whilethe-operative movements, even for the switch member and the controlswitch, are produced by; the stored forces. A 4

The selector consists of the following main parts: a contact field K,which; is a part of a flat bank multiple; abrush slideB movable up anddown infifront of thecontact field; a push rod S mounted adjacent theslide for-selectively inserting the brush sets; a setting mechanism Wfor the=brush slide with an included control switch and. a return deviceR, constructed-as a piston motor.

The three-row contact field K is divided into ten groups each of ten bythree contacts. Similar contact fields of other selectors are locatedside by side. The drawings only show both upper and lower contact groupsassembled in pairs. Between the contact fields are located bars whichhold together the bank multiple composed of partial banks, and acarrier-21 located underneath andfor -groups arranged behindthe'm. Thebrush sets are however, normally raised from the contact field, and areeach heldin an inoperative position by a locking lever 27. The brushsets can berendered operative separately. by me'ansof thepush rodmounted adjacent the slide."

- ;The push rod S is provided with ten pins 28, arranged in a line, nearprojections 29 of the locking levers'which are arranged in a parallelline; The. spacing ,of;the pins on the onehand and of thelocking leversand brush-sets on the other'hand are: so dimensioned that; after alowering of the slide from theupper position, (restposition) illustratedin Figures 1 and 2. successively through 1. 2 to 10 switch steps. thelocking lever of the first,i second to tenth brushset in the sequence.from. top to bottom has its projection just opposite one pinaloneflvhile at the same time the. corresponding brush set isspaced byone switch stepin front of its'contactgroup. If. therefore. after such alowering of the slide the rod is turnedwith tspins to within a shortdistanceof the slide. then a predetermined pin'pnshes the oppositelydisrosed lockinglever out of the. locking position. whereupon thecorresponding brush set springs underithe action of its springs into Thesetting mechanism is a set of apparatus which can be' completely removedI and which is suspended by means of two pins 30 projectingdaterallyfrom its upper end in two bearing members secured to the bars. Thesetting mechanism combines on a long base. plate-32, the switch member33 constructed as a rack. and the control member 34- alsojconstructedasa rack, together with theiraccessories.

I The rack 33 is guided for easy sliding movement by means of bearingmembers 35, provided near its ends, in two slots 36 of the base plate.The length of the .slots corresponds with the. length of stroke of thebrush slide to which the rack is connected during operation by theinsertion of the coupling projection 25 into a notch 37 The length ofstroke with the assumed size and group division of the contact fieldamounts to ten switch steps for the brush selecton and the lineselection which follows. A small additional amount in the length ofstroke is provided for disengagement particularly of the lower brushsets.

The selector during setting is driven by the weight of the brush slideand of the rack. The release of the movement of both parts is effectedby a ratchet pawl 39, engaging with ratchet teeth 38 of the rack, whichcan be withdrawn from the rack by the electromagnet 40. By short or longenergizations of the magnet there are produced short or long settingmovements. In the case of long movements, a centrifugal brake 42engaging with driving teeth 41 of the rack limits the speed to apredetermined maximum value.

Between the rack and the base plate, as shown in Figure 4, there isprovided an intermediate space in which there is slidably fitted in thesame slots as the rack the auxilia'ry switch member 43 shown separatelyin Figure 5. The auxiliary switch member is suspended on the rack by aspiral spring 44 which imparts to it an upward pull. A stop 45- at thelower slot' of the base'plate limits the upward movement of theauxiliary switch member in such a manner that its upper end 46 maintainsrelatively to the upper bearing member 35 of the rack a spacing which isequal toten switch steps. When the rack is lowered, the auxiliary switchmember remains stationary by reason of the action of the correspondinglytensioned spiral spring until the upper bearing member of the rack bearsagainst the upper end of the auxiliary switch member. The rack onfurther loweringthen moves the auxiliary switch member downwardly. Theauxiliary switch member maybe moved by the rack also in the caseof lessthan ten switch steps, if desired already after the first switch step bymeans of a' spring pawl 47, secured to the auxiliary switch member and atoothed bar 48 secured laterally to the rack. The spring pawl tendstobear against the toothed bar. The spring however, as will be describedhereinafter. is first pressed by the control switch from the toothed barand is only released for engage ment with the toothed bar after thebrush selection has been efi'ected. Norm ally therefore, the auxiliaryswitch member par-takes of the setting movement of the rack and of thebrush slide after the brush selection has been efiiected. at the latesthowever after the eleventh switch step.

The auxiliary switch member 4S'operating in the manner above described,is used mainly for changing over contacts which are dependent on thecommencement of selecting the separate lines. Figure 3 shows, forexample, a contact 49 which is opened after the first switch step of theselection of the separate line by the auxiliary switch member. In asimilar manner the auxiliary switch-member may also actuate othercontacts on subsequent switch steps calculated from the com mencement ofthe selection of the separate lines.

Another valuable use of the auxiliary switch member is shown by thenumber scale for reading oil the setting of the switch memher or of thebrush slide. This case concerns a scale for selectors withggroup andseparate line selection. Such indicating devices are known in connectionwith selectors having a switch member adjustable in two directions. Inconnection with multiple brush selections, however, wherein inthe caseof both selections a single switch member is moved indiscriminately inthe same direction, such indicating devices are not used. On thecontrary multiple brush selectors require a separate arrangement of theindicat .ing device and the introduction of such adevice is provided asthe plurality of brush sets or the multiplicity of the switch membersettings renders the correct meaning. ditficult. "i -l 1 The indicatingdevice illustrated 'isin the form of a two-part scale with: commonpointer, so arranged that thescale 50 fonthe group selection is providedon the switch member 33, while the scale 51 for the separate lineselection is stationary andthe common pointer 52 is secured to the saidauxiliary switch member 43. Figure 3v shows the indicating device in theposition of rest of the selector; Figure 3a-shows the changed p0s1- tionafter selecting, for example, the group 9, for which purpose the rackhas been lowered through nine'switch steps, and Figure 3. shows themodified position after further lowering the rack through five stepswhen the pointer has moved therewith through the last step number, sothat there is obtained the reading number 95.

The control switch (Figure 3) consists of a rod 34, arranged parallel tothe switch member of the selectorywhich is also slidably mounted inbearings 53 and is also drawn downwardly when setting by a spiral spring54. The releaseof the'rod is efiected by a doublelocking pawl(escapement) 55 in combination with a toothed bar 56 provided laterallyon the rod. The double locking pawl is held in the rest positionillustrated in engagement with the toothed bar by its own spring, and isrocked by a magnet 57 which when energized strikes by means of itsarmature 58, in the direction indicated by the arrow against the upperportion of the double pawl. The position of the control rod 38 shown inFigures 3 and 4 corresponds with the rest position. The release of therod by the electromagnet 57 is independent of that of the selectorswitch member 33. Also the number and length of stroke of the settingsteps of the control switch is capable of being suitably determinedwithin the limits of the total stroke of-the selector switch member. Inthe drawings, for the sake of simplicity, it is assumed that only foursetting steps are provided for the control switch, of which twoappertain to the armature attraction and two to the fall of the armatureof magnet 57 the first switch step being larger than the succeedingsteps for a reason to be described hereinafter.

The control rod 3& is provided at its lower end with two unequal cams 59and '60 as an example for the use of the control switch for changingover contacts.

Above the toothed bar '56, there is provided on the control rod anupwardly directed one armed lever 61 which in the rest position of thecontrol rod (Figures 3 and 6), ispressed towards a'base plate against aspring 64 by an outwardly bent arm 62 engaging with a member 63 havingan upwardly inclinedsurface. The lever is'also provided with a lateralprojection 65 embracing the control rod, which on the inner side of thecontrol rodhas the shape of a ratchet tooth as indicated by the brokenlinesin Figure 6. 7 v

When the control rod slides downwardly from the rest position in Figure6 the lever 61- moves from underneath the member (63) WltlI' th8inclined surface away from the base plate as'shown in Figure 7. Thespring-pawl 47 shown in Figs. 3 to 7 and which likewise moves from thebase-plate, follows said lever. This spring-pawl (47) snaps into therack 48;" Thus it will be apparent that the control switch on reachingthe inoperative position, directly couples the auxiliary shift-member 43with'the rack. 34.- by the release of said spring-pawl.

It will now be shown .how the control switch when leaving the restposition atthe same time mechanically operates the push rod S. Theactuation consists, in accordance with what has been described above, ina single rearward rotation of the rod. This movement is transmitted tothe rod by a push lever 66 mounted near the upper end 'of the'settingmechanism and on the rear side-thereof. Figure 3 shows the position ofthe lever in broken lines. when hanging the setting mechanism in itsoperative position, the lever 66, according to. Figure12' bears againstan inclined forwardly directed pin 67 on the push-rod S terminatingbehind the base plate 32. I A window 68 in the base plate (Figure 3)enables the engaging position of the lever 66 and pin 67 to be seenduring operation. Figure 11 shows the push 'lever and the rod in plan,while Figure 13-shows the rotation of the rod when the push lever movesdownwardly.

The push lever 66 during the first falling step'of the control rod ispulled downwardly with said rod indirectlyby an engaging pawl 69. WVhenthe push'leverhas reached the position shown in Figures 7 and 13, theengaging pawl strikes with a short arm 70 against the loweredge of thewindow (68) of the base plate. While the control rod continues itsmovement for a short distance, the engaging pawl :is disengaged by arapid rocking movement from the-push lever (Figure 8), whereupon thelatter and the push rod spring back immediately under their own springforces into the restposition; Thus the brush engagement (together withthe above mentioned coupling of the auxiliary switch member and thecontrol rod) is completed at the first response of the control magnet 57For the'two operations it is immaterial whether the control-magnet nowfalls immediately or remainsenergized for a longer period. Thismeansth'at" the carrying out of the further falling steps ofthe controlswitch (Figure 9) can take place at any-suitable time intervals.

For the purpose of returning the selector and control switch. the brushslides and the rack must always fall to their lowest position. Thisiseifected in a simple manner by continuously energizingtheelectro-magnet' 40. W'hen' the brush slide has reached its lowestposition it bearsxwith its weight on; the rod 7120f a piston motor R,actuated by compressedai'r'and .acting as a return device. Thisarrangement is known perse and acts in such manner that on theoccurrence of the piston load by a slide, a'valve reversaltakes placewhich allowscompressed airfrom a pipe 72 to flow under the piston. Thepiston then raises the slide, the rack and'the control rodsimultaneously into their'initial position. The movement of the controlrod during the return movementis effected by means of the rack. Thesecuring screw, shown in Figure 3, of the upper bearing member of therack has a pin like extension 73 which on the downward movement-of therack moves on the chain dotted line a?) indicated in Figure '10 andfinally overruns the projection 65, similar to a ratchet pawl, of thelever 61 whereby'this temporarily-escapes and then comes in front of thepins 7 3. During the upward movement of the rack the pin moves thecontrol switch upwardly therewith until by the slipping of'th'e lever 61under the member 63, according-to Figures 3 and 6, the lever moves awayfromthe pin, that is to say disengages the slide from the rack. The rackand slide then continue to move alone. The auxiliary switch member 43alone'moves upwardly under the action of the spiral spring 44 until thestop 45 limits its movement whereupon the partially expanded spiralspring is tensioned by the further upwardly moving rack. Shortly beforethe limit of the stroke of the auxiliary switch member is reached, thespring pawl 47 has been disengaged from the toothed bar 48 by theprojection 65 of the lever 61 slipping over the member' 63, which takesplace shortly before the end of the stroke of the auxiliary member so asto' withdraw saidpawl from said rack. When the slide and rack havereached their initial position, the piston in known manner shuts off thesupply of compressed air, whereupon the piston under the action ofgravity again moves downwardly, while the slide and rack are held by theratchet pawl 39 of the disengaged electromagnet l-O until the next useof the selector.

By the description ithas been shown that the main object of theinvention (simplification of a selector for group and single lineselection actuated by a control switch) is fully fulfilled by the stepswhich are taken (independent storing force setting and common foreignforce return of the selector and control switch member) in that for allthe numerous problems inherent in the adjustment of the said selectors,the result is achieved with inexpensive storing forces (gravity andsprings) which require little space. In particular, the application ofthis fundamental idea of the invention to multiple brush selectors ofbar form has been carried out in such detail that from this descriptionother analogous possibilities of use of the invention can be readilyeifeeted.

I claim l. A multiple brush selector with mechanical brush selection.comprising a contact field, a movable switch member carrying a pluralityof brush sets, a setting mechanism; said setting mechanism beingconnected to a control switch adapted to actuate contacts in variouspositions, and means for mechanically actuating a brush set selected bya setting movement of the switch member so as to move it into theoperative position for malting contact with the contact field; saidcontrol switch mechanically actuating the means for actuating a brushset in one of its positions.

2. A multiple brush selector with mechanical brush selection, comprisinga contactfield, a movable switch member carrying a plurality of brushsets, a setting mechanism, an auxiliary switch member in said settingmechanism adapted to be moved together therewith after a certainmovement of the switch member, a control switch connected to the settingmechanism and adapted in various positions to actuate contacts, i'neansfor mechanically actuating a brush set selected by a setting movement ofthe switch member so as to bring it into the operative position formaking contact with the contact field, and means for coupling theauxiliary switch member with the switch member; said coir trol switch inone of its positions mocha-nically actuating the means for mechanicallyactuating a brush set and mechanically controlling in one of itspositions the means for coupling the auxiliary switch member.

3. A multiple brush selector with mechanical brush selection, comprisinga contact field, a movable switch member carrying a plurality of brushsets; said switch member being adjustable in the same direction forselee-ting a brush set and for selecting a .contact of the contactfield, a setting mechanism, an auxiliary switch member in said settingmechanism adjustable together with the switch member after apredetermined movement thereof, means for coupling the auxiliary switchmember with the switch member, a two-part scale one part of which issecured to the switch member and is movable therewih and the other partof which is locally secured, and a point-er secured to the auxiliaryswitch member and moving therewith.

A multiple brush selector with mechanieal brush selection, comprising acontact field, a movable switch member carrying a plurality of brushsets, a stored force for moving the switch member, a setting mechanismregulating the movement of the switch member; said setting mechanismbeing connected to a. control switch adapted in various positions toactuate contacts, a stored force for moving the control switch, a magnetfor regulating this movement of the control switch, and means formechanically actuating a brush set selected by a setting movement of theswitch member for bringing it into the operative position for makingcontact with the contact field said control switch mechanicallycontrolling the means for. actuating a brush set in one of itspositions.

5v A multiple brush selectorwith mechanical brush selection, comprisinga contact field, a movable switch member carrying a plurality of brushsets, a stored force for moving the switch member, a setting mechanismregulating the movement of the switch member," said setting mechanismbeing connected to a control switch adapted in various positions toactuate contacts, a stored force for moving the control switch, a,magnet for regulating this movement of the control switch, means formechanically actuating a brush set selected by a setting movement of theswitch member for bringing it into the operative position for makingconta ctwith the contact field; said control switch mechanicallycontrolling the means for actuating a brush set in one of its positions,and a driving device applied outside for renewing the stored forcesexpended when setting the switch member and the control switch.

6. A multiple brush selector according to claim 5, wherein said drivingdevice moves the switch member and the control switch in a directionopposite to the setting movement.

7. A multiple brush selector with mechanical brush selection, comprisinga contact field, a movable switch member carrying a number of brushsets, a stored force for moving the switch member, a setting mechanismregulating the movement of the switch member; said setting mechanismbeing connected to a control switch adapted in various positions toactuate contacts, a stored force for moving the control switch, a magnetfor regulating this movement of the control switch, means formechanically actuating a brush set selected by a setting movement of theswitch member for bringing it into the operative position for makingcontact with the contact field; said control switch mechanicallycontrolling the means for actuating a brush set in one of its positions,a driving force applied at the outside for renewing the stored forcesexpended when setting the switch member and the control switch; saiddriving device acting directly on the switch member and moving the sameinua direction opposite to the setting movement, and automaticallyoperating coupling members for connecting the control switch totheswitch member during the return movement thereof to initial position: gI

I 8. Amultiple brush selector with mechanical' brush selection,comprising a contact field,-a movable switch member carrying a pluralityof brush sets, a setting mechanism; said setting mechanism beingconnected to a control switchadapted in various positions toactuatecontacts, and means for' exerting a' temporary ush upon a brush setselected by a setting movementfof the switch member for bringing it intothe operative position' for making contact with the I contact field;said means 1 including intermediate members actuated by the controlswitch in one of its positions and automatically released from'thecontrol switch 'after 'exertin g the pushjon the brush set. v

9. A multiple brush selector according to claim 8, wherein said switchmember and saidsetting mechanism'are formed as separate exchangeablesets of apparatus, and said means forexerting a push 'is mounted in astationary position adjacent the; switch member, while said c0ntrolswitch and said intermediate members are structurally connected tothesetting mechanism.

10. A multiple brush selector with. mechanical brush selection,comprising a contact field, a -movable switch member inf'the form of arod carrying a plurality of brush sets, a setting mechanism constructedin elongated form; said setting mechanism being connected to a controlswitch and said control switch being constructed in the form of a rodin' accordance with the elongated shape of the setting mechanism andbeing adapted in various positions to actuate contacts, and means formechanically actuating a brush set selected'by a selecting movement of'thetswitch member so'as to bring it into operative position for makingcontact with the contact field; the aforesaid control switchmechanically actuating the means for actuating a brush set in one ofitspositions.

FRIEDRICH MERK.

